Why won't my player read a recorded disc?

Failure to read recorded discs in standard CD and DVD players.

This is a subject raised by my good friend Keith V. I wish he hadn’t! However, I’ve ended up with quite a bank of information which I thought might make good subject material for a blog posting. I know he’s going to read this because I haven’t copied it to his email address (one way of getting traffic!). So, thanks Keith, I hope some of this answers your question! I haven’t done one for a little while, so here’s a post-and-a-half! -

A word of warning before reading on:- Have you ever noticed the yellow label that is on the back of CD, MD and DVD players (also the older laser disc players)? One is also frequently placed on or near the laser mech itself inside the machine. This is warning of laser emission which may damage your eye sight – never look directly into the laser, you could end up with impaired vision. The laser output is not something you can see, the emission that is doing the work is in the infra-red region of the light spectrum – out of the visible light range of our eyes. A number of customers that have “had a go”, insist that the laser is OK because they can see a red glow within the lens. This red glow is a visible portion of the light generated, it’s not the bit that actually does the work. It is a bi-product. Don’t forget how a disc is “burnt” in a recorder. The phrase may give a clue. In a recording machine the laser is powerful enough to locally heat and permanently change the dye on the reflective surface of the disc. Think safe and don't look directly into an exposed, working laser.

Failure to read recorded discs in standard CD and DVD players.

This is something that I come across frequently!

The first thing to consider is if the machine used to play such discs. If this is the case, chances are that something within the machine has changed. I find that normally the electronics are pretty robust and reliable. The problem is usually down to laser ageing or contamination. I have theorised a number of possible processes that can take place.

Age related

The laser diode itself can go "low emission" – put simply, the torch by which the CD mech is trying to read the data is fading. Lasers are a bit like light bulbs, they start wearing out from the moment you switch them on. Burnt discs are harder to read than standard production discs. One obvious observation is that they are less reflective, they have to be in order that energy from the recording laser can be absorbed by the surface for the process to take place. Because they are harder to read, it follows that they could also be the first to appear problematic when the laser is failing.

Contamination

 

Contamination of the laser pick-up (and other parts of the machine, for that matter) can be a problem. This can be in the form of several types:-

• Dust – can be the usual stuff or pet dust

• Talcum powder – typically in the bedroom player

• Pet hair

• Fluids – spilt drinks, flowerpot overfill, pet fluids (typically cat pee!) – these will often render electronics un-repairable anyway!

• Smoke – it’s surprising how the number of problematic CD and DVD players from pubs and clubs has diminished with the smoking ban (same goes for projectors).

These are the killers of lasers. Surface contamination of the lens is not the problem, it’s deeper inside the laser assembly where the contaminants get into the internal optics where the issue becomes non-reversible. Even a service engineer can’t get to these areas to clean up. A single particle of dust in the right place can reduce the light output or deflect the beam as to make the laser useless. Replacement is the only cure.  By the way, I'm not against the use of lens cleaning discs.  So long as they are used regularly they can keep down the level of contaminants on the laer lens itself.  If you wait until there is a problem, usually they don't work.  Thats because the laser needs to read the TOC of the disc, if it's lens is too grubby, it will not register a disc is in the tray and therefore it won't try to play it.

Burnt discs vs. commercial discs

Commercial discs are “stamped” using a master. Obviously "burnt" discs are produced by a method different to that which commercial discs are made. This method, quite obviously, may not be as accurate a recording as a commercially made disc. All players have built in error detection and correction algorithms in the decoding circuitry/software. The data on a disc is encoded and the decoding in the machine are done in such a way that these errors show up. The player will attempt to anticipate what the data should have been and substitute a correction.

Errors can be due to a number of reasons including:-

• A bad "burn" - random failure of disc writing, see below

• Writing burn speed too fast  (common – audio CD’s shouldn’t really be burnt faster than 4x)

• A fault with the burning machine including dust/contamination on the laser lens

• Minute air bubbles in the plastic of the disc

• Cheap discs (one thing I’ve heard very frequently is what a fantastic price a person has paid for discs in the supermarket or on the net, then in the next breath how many they are throwing away because their machine didn’t write properly. OK, there’s a pattern here!)

• Low quality media that has a poor “shelf life”

• Cheap recorders that make mistakes

• Scratches on the playing side of the disc

• Sticky labels – the glue can attack the disk surface (the disks own label on is the only protection between the outside world and the reflective surface of the reading side)

• Scratches on the label side of the disc (same as reason above)

• Discs written on by a sharp device such as ball point pen or pencil (same as reason above)

Errors can also happen when using a PC because of the following:-

• Dust getting into your machine when you open the tray - make sure the outside of the burner is clean to avoid this

• For maximum performance use the “Disc-at-once” mode – there is a greater chance of errors occurring if you use “Track-at-once”

• Fast burning speeds can cause buffer underruns

• Fast burning speeds often cause lower quality burns

• Don’t run background programs or screen savers – increased processor activity can cause buffer undrruns

• Defragging your hard drive before burning a disc will reduce the risk of your machine being erratic during the burn

• Don’t leave sessions open, always finalise your discs

• Make sure that your player can play the formats that your burner can produce

• Make sure that your media can run at the speed that you intend to burn

• Make sure that you burner firmware is updated

• If using DVD+R/+RW media, making sure that the “Booktype” field (bitsetting) is set to DVD-ROM will give a higher compatibility yield

But what if the problem appears to be none of the above?

Now, there are many methods, different software/firmware and design shortcuts that manufacturers use in the production of a machine (recorder or player). Different types of laser also make a difference to the way a machine retrieves the data. Many high street machines are built to a price. This, believe it or not, does affect the quality of the machine and the playback! I have found that, generally, the better the machine (and, therefore, the more expensive it is), the better equipped it is for detecting and correcting these errors. After all, if you spend a lot of your hard earned on a top-of-the-range Hi-Fi system, you'd hope that the music it played would be more lifelike.  The problem arises when a machine starts detecting multiple errors. Obviously, there could also be a problem within the machine – the manufacturer didn’t expect you to be playing a “low quality” disc and didn’t allow for a high degree of correction, or, the correction circuitry is overwhelmed and simply can’t keep up with the detection circuitry. The player could actually be trying to tell you that the disc you are attempting to play is rubbish! (It doesn’t conform to the recognised recording standard, there are a number of these depending on the type of recording and its intended use – red book, orange book, yellow book, etc.) The fact that the “bad” disc plays in a cheap machine may only be down to the fact that the cheap circuitry recognises the data as roughly correct and lets through some of the errors! This all does beg a compatibility issue.

Don’t forget that the media may not be clear of suspicion as well. If you do find a brand and type of media that works with both your burner and your player, stick with it and buy large quantities. Manufacturers do have a tendency to change the quality and their media ID.

Early machines

Don’t forget that the CD player was introduced in 1982, the CD-R wasn’t conceived until 1988 and wasn’t readily available until 1990. It is unlikely that you will get an early player to read a CD-R. CD-RW didn't come onto the market until even later.  The same may be true of DVD recordable discs and early DVD players.

CD players in “Midi”, “Mini” and “Micro” systems

The “Midi” system became popular around the late eighties. The tendency to build-in the CD player caused me to come up with some interesting theory. All was well with the CD as an add-on, optional, box. It usually sat at the bottom of the stack. When it went inboard, things were still fine…. as long as it was at the bottom! When the high street decided that vinyl was dead and the record player was no longer a necessary inclusion in the package, the CD player tended to move to the top of the stack and was most definitely integrated as part of the whole. That’s when the problems began. All of the heavy power consuming, heat producing components tend to be in the bottom of the box – power transformer, power supply PCBs, amplifiers and their heatsinks, etc. Probably the best place to put them. The point here is that, by simple convection, heat rises. There are normally ventilation holes in the back or sides or both, sometimes in the top. Cool air from the room is drawn in to replace the heated air which is rising and (hopefully) escaping from the top. Along with the cool air, is drawn any contaminants which the room’s air may contain. As this air is heated and it rises, so do the contaminants, which are very nicely deposited over the contents of the unit. Especially the CD player which is at the top. The laser is now dirty and cooked! Also it won’t read the data too well. These days, we now have “Mini” and “Micro” system as well, some with DVD decks instead of CD. You know what comes next.

You might say the disc drive in most PC’s is at the top and has a reasonable lifetime…. This is very true, but all the PC drives that I’ve come across are reasonably sealed in their own tin box, which is mounted into the tower. Dust can’t get in apart from through the front opening tray.

Separate Hi-Fi decks usually go on for a fair while without messing about. In fact, as touched on above, smoke can be the real killer here. Unfortunately, smoke particles are tiny and along with any vapours that they contain, they get everywhere. If the player is on 60 a day, you can bet that the laser is well oiled with tar, etc! They don’t read very well with this encumbrance! There are no hardworking, heat producing power supplies or amplifiers inside a stand alone player. Many of them don’t have any ventilation in the casework, it’s not necessary.

Media lifetime – how long will your recordings last?

When CDs were introduced, back in 1982, they were portrayed as being pretty much indestructible and would play in any state. I’ve searched everywhere to include a clip of the Tomorrow's World episode where a demonstration was done by spreading strawberry jam on a CD before trying to play it.  I can remember a man in Laskeys jumping up and down on a CD and a crowd of onlookers falling about as it skipped wonderfully on playback!

Recordable discs give the impression of a similar permanence and manufacturers have claimed a lifespan of anything between 10 and 200 years. However, tests have been carried out, by professional bodies, on discs stored for less than 2 years and found that a number had become unreadable.

This is not to be taken that all discs last for less than 2 years. Many recoded discs have been kept for much longer and have given no trouble. What can be drawn from all of the information contained here is that if you save precious documents, photos, music, video content, etc. on recordable discs:

• Use good, branded media

• Avoid self-adhesive labels

• Use only felt-tipped or “CD” pens for writing on the disc label area

• Store your CDs in protective “jewel” cases in a dark, cool, dry location

• Make multiple copies of important items

• Copy your data to new discs (or new formats as they appear) every 3 to 5 years

My own conclusion about recordings

As a rule of thumb, I have learnt to adopt the attitude that recorded DVDs are only guaranteed to play back on the machine that made the recording! If you do get a result in something else, it’s a bonus! CDs aren’t so bad and usually work fine.

And now, something completely different - "CD Rot", "CD Bronzing", "Disc Rot"

This I've come across (so far) only in commercially recorded CDs.  It does exist, I have several examples.  In the most frustrating varieties, some sort of chemical action within the CD has attacked the reflective layer and "holes" appear in the silvered (or gold) finish.  The areas around this problem are often tainted an orangey colour.  Worse case scenarios end up looking a bit "lace-edged".  Needless to say, playback is impaired.  It seems that once this does show up, it "spreads" through the entire disc rendering it useless.  This has happened to a number of my "limited" or "special" edition discs, which I now don't seem to able to replace.  Here's another example. The only good news is that it doesn't seem to be contagious!

Note to the reader

Some of the information contained here is based wholly on my experiences in testing, fault finding and servicing machines. Some individuals or organisations may not agree with my views! I have also tried to keep this as non-technical as possible, such that the average “man in the street” can understand what is being said.

Some more gig dates for your diary

The Shrinking Violets

My good friends Al and Verite have sent me some new gig details, which I shall pass on:-

The Star Inn, St Just - 27th March.

The Star Inn, St Just - 17th April

The Harbour Pool Club, St Ives 1st May

The Star Inn, St Just - 19th May

O'Flanigans, Penzance 29th May

Al Horton on guitar, Verite Alexander on vocals and a little Japanese guy called Sony on backing.  He's very good, he plays bass, keys, percussion and more, all at the same time too!  But seriously, all the backing tracks are put together by Verite, they're not "bought in".

The style of music these guys play is pop-rock / rock, the sort of stuff that usually goes down well anywhere.  Al is quite an acomplished guitarist and very adaptable.  Verite's vocals are just mind bogglingly dynamic.

May well see you at some of these.

Cornish Ale Festival - Tasting Notes

PURELY CORNISH ALE FESTIVAL

Lower Quarter, Ludgvan, Penzance, Cornwall

Don't forget the "Purely Cornish" Ale Festival at The Old Inn, Ludgvan (near Penzance) this weekend. It's running from Friday evening, 26 February, to Sunday evening, 28 February.

I will be there during Friday evening and Sunday afternoon, see you there!

Definately don't forget -

All guest ales are only £2.00 per pint!

TASTING NOTES

ALES:

All Saints Brewery
St. Piran 4.0% ABV. No tasting notes available.

Coastal Brewery
Angelina 4.1% ABV. A hugely successful beer, golden colour, citrus sweet aroma, crisp hoppyness, clean and refreshing.

Keltek Brewery
4K Mild 4.0% ABV. A traditional dark mild but fruity in taste with great character. It is one of those products that catch the eye at the pump. Winner of the Mild Ale Class, SIBA Maltings Beer Festival.

Keltek Brewery
Golden Lance 3.8% ABV. Clear golden coloured with a fruit aroma and tangy citrus flavours. Very smooth with a full hop dry finish

Lizard Brewery
Kernow Gold 3.7% ABV. A light, golden ale. Crisp and refreshing, the malts used are Maris Otter Pale Malt with a touch of Amber Malt which gives a biscuity note. Challenger and Fuggles hops, finished off with Styrian Goldings which give fresh citrus flavours.

Wooden Hand Brewery
Cornish Mutiny 4.8% ABV. This fine beer enjoys a dark rich colour with a distinctive 'hoppy' character and a slightly 'biscuity' flavour.

Wooden Hand Brewery
Black Pearl 4.5% ABV. A tasty dark stout with a rich nut and hop prickle and a dry chocolate finish. Ingredients: Marris Otter malted barley, flaked and roasted barley; English grown hops.

Blue Anchor
Spingo Middle 5.1% ABV. Spingo is brewed from water drawn from The Blue Anchor's own well. Most of the fermentable sugar comes from malted barley. The beer is fermented for long enough to produce the required alcohol content but leave just a hint of sweetness which was common in Cornish beers of yesteryear.

Skinners Brewery
Heligan Honey 4.0% ABV. A light refreshing bitter, pale amber in colour with distinct hoppy overtones and the subtle addition of real Cornish honey.

Skinners Brewery
Ginger Tosser 3.8% ABV. Designed for red-headed pancake tossers (of course! What did you think the name was referencing…. for shame!). Originally created to aid the celebration of Pancake Day, now a permanent fixture among the Skinner’s stable. Made with only the finest Cornish Honey.
Clear medium yellow orange color with a average, frothy, fair lacing, mostly diminishing, off-white head. Aroma is moderate malty, toasted, citrus, ginger, toffee notes. Flavor is moderate sweet and light to moderate bitter with an average to long duration. Body is medium, texture is oily, carbonation is light.

Skinners Brewery
Figgy’s Brew 4.5% ABV. This is the maltiest of the Skinners regular range and slightly darker in colour. An expertly balanced blend of malt & hops, premium strength, full flavoured with a smooth finish.

Skinners Brewery
Cornish Lager 5.5% ABV. Golden/Blond Ale. Clear golden with large white head. Sweet malty aroma with caramel notes and fruity flavor. Ends sweet.

Sharps Brewery
Doom Bar 4.0% ABV. Somewhat hazy amber body, small white foam. Nice aroma, a good bit of spicy British hop and crystal malt toffee sweetness. Smooth texture, low carbonation, medium-lean body. Good hop and malt presence on the body. Solid bitter finish.

Sharps Brewery
6 Hop IPA 3.8% ABV. This is a brand new brew from Sharps, hence no tasting notes as yet. The Old Inn is privileged to have the very first off production, so being début here this weekend.

St. Austell Brewery
Cockleroaster 4.5% ABV. A newly launched ale, this is the first new beer in a seasonal ale programme launched by St Austell Brewery for 2010. Said to be a "rich dark stout brewed with pale and roasted malt with lashings of dark chocolate and finely chopped chillis.
Head Brewer, Roger Ryman, said: "We're really excited about launching Cockleroaster. Customers should taste the chocolate as the main flavour and get a subtle taste of chilli with the aftertaste."
Chillis from Devon.

Choughs Brewery
Serpentine 4.5% ABV. Reddish amber with a white head. Not best described as a bitter, more like crossing over to an Irish red Ale. Smooth and creamy with hints of sweetness initially. A fleshy fruitiness with a hoppy bitter finish. There is a lemony tartness at the end, quite quenching and full. Ingredients: Pale malt, crystal malt, chocolate malt, wheat malt. Hallertau hops.


CIDERS:

Skinners Brewery
Press Gang 4.8% ABV. Still, medium cider, described as light and refreshing with the delicate aroma of ripe apples.

Healeys Brewery
Rattler 6.0% ABV. A light haze. Sweet, slightly woody green apple aroma, hints of tartness. Prickly carbonation. Honeyed sweetness. A reasonable balance of the sweet and tart.

Headley’s
Special Cider 5.0% ABV Very locally produced. No tasting notes for this one, try it and see!


GINGER BEER:

Wheal Maiden
Grandma’s Weapons Grade 5.5% ABV Traditionally served “on gravity” (straight from the barrel). Gingery (!), fiery hot, fizz provided by natural fermentation.

Read down my previous blog for  further info on the pub.

Something a little different....

A CORNISH ALE FESTIVAL
Lower Quarter, Ludgvan, Penzance, Cornwall
Here’s something a little different for you, many a friend who knows me also knows my passion for a pint or two of real ale or wheat beer.

One of my favourite local tap houses is staging a real ale festival at the end of this month. This is an ale festival with a twist – purely Cornish.

The venue is The Old Inn at Ludgvan. Friday 26 Feb to Sunday 28 Feb.

The event is to feature 15+ beers, ciders and alcoholic ginger beer from:

All Saints Brewery

Blue Anchor Brewery

Coastal Brewery

Healey Cider Farm

Hedley’s Apple Orchard

Keltek Brewery

Lizard Brewery

Skinners Brewery

Sharps Brewery

Wheal Maiden

Wooden Hand Brewery

AND all guest ales at only £2.00 per pint!

More Info About The Pub

There's always a warm welcome from Nick, Gaye and all the staff at their traditional 18th century pub.  In addition to the main bar and eating area, the pub has a games room with Pool Table.  There's an open fire in each room and a piano.  Check out the room sized mural of "Old Ludgvan" in the snug.  The Old Inn is children and dog friendly too.  Definitely a "feel good" atmosphere.

There's usually a choice of three real ales on hand pull, sometimes four.  A strong alcoholic ginger beer is also stocked, Grandma's Weapons Grade, brewed at Carharrack just outside Redruth.  Other "specialist" brews on draught include Cornish Rattler, Cornish Lager and San Miguel.  There are, of course, numerous other taps and bottles offering the normal other choices.

The kitchen offers good food in the style of traditional pub grub, with all ingredients sourced locally where possible.  But also, if you are into pizza, this is a must go pub for you.  On a warm evening, sat outside with a glass of San Miguel and one of Nick's pizzas, all I need to do is close my eyes and I'm back on holiday in the Med or Canaries!  These delights are prepared fresh while you watch, they are not pre-packed, frozen or whatever - you will see the dough being prepared and you will see fresh ingredients go onto your pizza.  If you fancy something different to the menu, providing Nick has the ingredients, you could make up your own personal recipe.  Though powered by electricity, the oven is a proper, purpose made stone based Pizza oven.

Don't take my word for it, please click here and read some reviews.

 

Good News For Independent Retailers

Consumers and independent dealers please read this!

Supermarket watchdog welcome…
...but more is needed to help small shops and suppliers

Following below is an extract from January's edition of the FPB (Forum of Private Business) news letter.  The contents of this brought a smile to my face, at last someone has recognised what the supermarkets are up to.  This is a welcome start to the policing that small independent retail businesses need to combat the unfair trading that is going on with these big giants.  I have commented many times about their practices to various parties and organizations.

When it comes to service, it may be that the general public is beginning to have second thoughts about buying from these outlets. Of recent times the number of complaints that I have received about x, y or z supermarket have risen enormously. A 32” LCD TV at £599.97 is still a major purchase as far as the man in the street is concerned and when they find that it won’t do what they expected (connectivity / performance for home cinema or computer are a common issues) or worse, it develops a fault, there is often no recourse with the store concerned. You’re stuck with it! For a third party to become involved in the repair of such an item, providing an estimate can be quite expensive and many won’t even look at a large screen TV without a major deposit or fee up-front. Even if there is an issue which could be down to manufacture, the parent company usually won’t even discuss the problem with the owner until he can provide a written estimate of the repair cost and full fault diagnosis from a recognised, approved repairer. The repairer is usually not obliged to negotiate for the owner. There are definite benefits to be had by buying from a local independent dealer at what might appear to be a less attractive price. Check out your local independents, they might not be as expensive as you think. Most have got workshop and back-up facilities for the brands that they support. Better still, they have experience under their belts. Ask their advice and buy a brand name that they recommend, it’ll usually be one that you recognise – Toshiba, Panasonic, Samsung , etc. They will have seen numerous of the Yamatachi type brands, from the local supermarkets, brought in for repair by less fortunate individuals, and most of them will have ended up as landfill.  And remember The Sale of Goods Act if you do fall foul of a product that doesn't do what it says on the tin, or if you suffer a premature breakdown - "Sorry Sir, it's just out of warranty" isn't good enough.

Please remember my favourite quotation:

“The bitterness of poor quality lingers long after the sweetness of low price is forgotten.”

The extract:

Forum of Private Business (13 January 2010)

Small suppliers are finally being given protection from supermarkets in the form of an ombudsman, but independent business is calling for further measures to help both suppliers and shops.

The FPB is welcoming today's news that the Government has accepted a recommendation for a body to enforce the Groceries Supply Code of Practice (GSCOP). It was made by the Competition Commission in 2008 after a two-year inquiry into alleged abuses in the groceries market.

In February, the Government will begin a consultation on how best to enforce the GSCOP, including identifying the nature and powers of the ombudsman.

However, there is concern that many suppliers will not come forward to complain about poor treatment at the hands of supermarkets out of fears they will cease to do business with them. A guarantee of anonymity in the complaints process could address this problem.

Research carried out by the FPB shortly after the inquiry was launched found that 76% of respondents wanted a watchdog to oversee the GSCOP, which covers supplier issues such as late payment and retrospective pricing as well as consumer complaints.

However, another survey revealed that 74% of business owners believe they should be guaranteed anonymity when giving evidence to both the Competition Commission and the Office of Fair Trading (OFT).

Further, the FPB believes that the Competition Commission's recommendations for a ‘competition test', which has yet to be implemented, designed to prevent individual retail giants from dominating local markets, would simply allow other big supermarkets to compete and offers little to struggling high street shops.

In its preliminary findings, the Competition Commission said that, between 1999 and 2006, the entry of a supermarket into a town centre had caused more existing independent grocers and local markets to seek alternative locations than it had encouraged new retailers to move in.

As long ago as 2006, the All-Party Small Shops Group warned that, with around 2,000 small shops closing every year, the majority of the UK's independent retailers could disappear by 2015.

Now, with the recession driving more and more shoppers to discounted supermarkets, the FPB is concerned that the situation is even worse for shop owners.

The Competition Commission's investigation has called into question some other alleged business practices of supermarkets, such as below-cost pricing, where large retailers significantly undercut market prices on the high street by selling certain products at a loss in order to soak up trade, making up these losses on other product lines.

The FPB has been critical of previous investigations into the practices of large retailers, including the £116 million in total fines imposed in 2007 following the OFT's probe into the dairy market price fixing scandal – a drop in the ocean compared to the supermarkets' vast profits.

"Small suppliers and retailers continue to suffer as a result of supermarkets' anti-competitive practices. One of the main problems is that many suppliers feel intimidated into silence and do not speak out; a situation we need to change," said the FPB's Chief Executive, Phil Orford.

"While a dedicated watchdog for these businesses is welcome, it does not go far enough to hold large retailers to account or to address the need to reinvigorate small shops on our high streets and the communities they serve."

Permission was obtained for the reproduction of this article.

More Local Gig Info

Blues Connection playng at Mousehole, Friday 29th January

My good friends Blues Connection are playing close to my home once again on the 29th of January.  The venue is the Ship Inn at Mousehole just the other side (west) of Newlyn and Penzance.  Well worth getting out to see/hear, the Ship also serves up a decent pint and dishes up a good meal if you want to make a full evening of it.

As you may have guessed from their name, this is a blues band!  It's a blues-rock quartet.

Blues Connection are:-

Scott “Maltloaf” Jeffery, fronting the band with his belting vocal technique, has been part of the Cornish music scene for many years and has lead many a good local group. He is a well-known and popular singer throughout Cornwall.

Phil Jones on guitar has been in the past an international artist, touring extensively across the UK and Europe, supporting the likes of Jools Holland, Buddy Guy and Otis Rush. Of recent times he has played for a good number of local bands - The Hothouse Playboys, The Cadillac Kings and Wammajamma to mention a few.

Emma Spires on bass guitar is an experienced musician who has played with many blues and rock outfits, including Mississippi Burning, Crosstown Traffic and Ragtime Millionaires.

Mark Wilkin on drums has played for a wide range of artists including Bill Bailey, Boney M, George McCrae, Brix Smith, Noctorum, Adrian Borland (The Sound) and Rosebud Choir.

See you there, don't be late.

More information:-

http://www.bluesconnection.co.uk/

http://www.pznow.co.uk/gedkingsford1.html

The First Repair

So, your CD player won't read or play discs anymore?
Well my little Denon UD-M31 hasn't for a while.  Now that I've got my office and workspace finished and equipped, I thought it's about time that this old guy had a new optical pick-up (laser).  So, it promptly became the first repair conducted in this new space.  A number of symptoms can be apparent when the laser is wearing out in a player:

1. On loading the disc nothing at all happens.
2. As 1 above with the usual spin-up "shhh" sound from the mechanism.
3. As 1 above with a quiet "tick tick tick" sound from the mechanism.
4. As 1, 2 or 3 with "no disc" appearing on the display.
5. As 1, 2 or 3 with zeros appearing on the display instead of the TOC information.
6. The machine takes longer that normal to read the disc contents.
7. The machine reads the disc contents but then won't play.
8. The machine is very selective with which of your discs it will or won't play.
9. The machine won't play or has difficulty playing CD-R discs (older machines and some commercial players aren't designed to play these).
10. The laser jumps and skips whilst playing the CD and you hear audible ticks or noise during play.
11. Playback stops part-way through the disc.

Beware of dirty or damaged discs as they will also cause some of the faults described above, so if in doubt check the disc for the obvious first.  This is a major problem that I have encountered with commercial establishments over the years.  Despite the fact that the CDs are all scratched up because they have been all over the bar and on the floor naked, and/or they have a nice coating of stale beer, which by now is growing a few cultures, the owner still wants to blame the machine!  I think it's something to do with that "general knowledge" that you can't damage a CD (there could be more about this in another posting).

Back to the repair

Some of these "All-in-One" units can be annoyingly difficult to get in and at the pick-up, so beware if you're going to attempt laser replacement yourself.  With this machine, the top has to come off first followed by the front panel.  Behind and at the bottom of the front panel is an incredibly delicate ribbon cable which you won't know is there until you've broken it, unless you have the service manual and you've studied it first!  The mechanism is shrouded in printed circuit boards, so there's some unplugging of more incredibly delicate cables and the removal of the PCB sitting on top.  Unless you've had the experience, it's best to take the mech. out to change the laser, this means more unplugging and more PCBs.  It's usually a fairly straightforward mechanical disassembly to get the laser out of the assembly, but this one came complete with the sub-chassis, so it's very easy.  Just one or two more delicate cables to remove out of the way!

It's great when a laser comes as a complete unit like this.  It means you're also changing most of the moving mechanical parts, including the spin and sled motors, together with the pick-up.  These are items that may well also be worn and ready to cause you more problems.  So, from a preventative maintenance point of view, it's good practice to fit the whole thing whenever you can.

So, having got this far, the rest is easy - reassemble in the reverse order.  Just hope that you can remember where all the bits all came from!  Fitting the ribbon cable back in the rear end of the laser is usually fiddly at the best of times.  With this machine, you need hands that are the size of a new born baby's and fingers that work like octopus tentacles!

Once reassembled, you're not finished yet.  Some makes/models will be OK with no further action, but this and several other machines I have come across still may not work properly yet.  There is a calibration procedure to be carried out (not all lasers perform identically).  With some units, this is done using laboratory instruments like an oscilloscope and a signal generator.  Measurements and corresponding adjustments have to be made to the machine's electronics.  But, with this player, the calibration is automated within electronics and software.  First you have to access the service program and then you need to follow a set pattern of key entries, check for responses indicated on the display and ultimately perform the auto-calibration.  Clearly, without the service manual, there is no way of knowing how to do any of this, or even if you have to.

If this hasn't put you of doing it yourself, there are only a few other minor issues to consider:

• Some lasers have several variants, you'll need the exact one.
• Some lasers are incredibly difficult to identify without experience and information.
• Similarly some have been replaced with an equivalent.
• Try to only fit original laser types, a lot of the after market replacements (particularly those for obsolete models) are very fussy and some don't work at all.  There are a few machines in which I now won't replace the laser because the original is no longer available and the replacements are too unreliable.
• Laser pick-ups are sensitive to static electricity and unless you are properly grounded whilst undertaking the procedure, the unit could be damaged by a discharge.  Worse, this might not show up straight away.
• Some machines require special tools or software, as well as the laboratory equipment, to make the calibration adjustments.  These are often only available to trained dealers from the manufacturer.
• Shock hazard - be aware of danger.  There can be exposed mains voltages inside the machine, make sure you know where they are especially if you intend to operate the machine partially disassembled.
• Blindness hazard - be aware of danger.  Never look directly into the laser when it is operating, you could damage your eyesight.  The laser light is at the infra-red end of the spectrum and is invisible to us, so you won't know if it's there or not.  The faint red glow that you may see is only a visible component of the total output and is not an indication that the laser is worn out.
• Trying to fix cheap supermarket CD players and CD-ROM drives is futile - they are very inexpensive to replace.  Don't waste your time!
• Even if the machine exhibits any of the symptoms mentioned at the beginning of this post, don't assume that the laser is to blame.  In my experience of recent machines, it probably is, but there are many components in the "front-end" circuitry which can give the same response.  A more scientific approach to prove it is often beneficial, without this your new laser may have a short lifetime.

Why did it stop working properly anyway?

This is a question I am asked frequently.  There are numerous reasons, some I have theorised myself.

The answer you really want to hear is "old age".  I think a good analogy, which most people understand, is lasers are a bit like a light bulb, they start wearing out from the first time you switch on.  Most lasers seem to have a lifetime of around 5,000 hours.  In domestic terms this equates, quite often, to 7 years plus (with average use).  With commercial use, this would be reduced to 2 or 3 years - a lot of venues are now open 25 hours a day, 8 days a week; the laser isn't going to last forever!  This is all providing (in my experience) that it's a decent machine to start with, and there are exceptions that live longer.

Lifetime also has a lot to do with cleanliness.  In the past, I have handled many machines where I have felt the laser pick-up has suffered premature failure.  Sometimes this is down to design and other times it is some external contribution.

Traditionally, a Hi-Fi tower system had the turntable at the top.  When CD came along in 1982, the tower system had become known as a "midi" system and the optional CD player was placed underneath the whole stack.  Then CD players became a must and they were built into the bottom and the optional turntable was placed on top.  This all seemed fine until eventually the turntable was deemed a non-requirement and the CD player migrated to the top of the box.  That's when the trouble started.  Right or wrong, I have deduced the following:  All the heavy power consuming, heat generating components are in the bottom of the unit - mains transformer, power supplies, the power amplifiers with heatsinks and so-on.  Ventilation is provided in the rear or sides and draws in cool air.  The cool air warms up inside the machine and rises due to convection, eventually exiting via the position of the CD player.  Simple.  Except, along with the cool air, contaminants like dust, pet hair and cigarette smoke are also drawn into the box.  The rising warm current of air does two things to the CD player before venting back into the room - heats it up and deposits a good deal of the contaminants into the workings.  The components can be cleaned, re-lubricated, etc., but the problem with a laser is that you can't get to the internal bits - the laser diode, mirrors and lenses.  Once a laser is contaminated in this way, in my book it's useless.  The only cure is replacement.  Any amount of cleaning of the laser which may get it working again is usually a temporary solution.  I never pass a machine as fixed when this is the case.  It may be OK as a temporary situation so the customer can find something else, or maybe to buy some time whilst funds allow for a new laser (which might be expensive), but usually these machines will come back within a short period of time.

Out of all CD players that I have had for repair or investigation over the last 10 years or so, about 20% were serious Hi-Fi separates.  The vast majority of these were suffering effects of age.  Of the remaining 80%, the vast majority were all-in-one units, midi, and (now) micro systems with failed lasers.  More than half of these showed physical evidence of dust, pet hair, cigarette smoke, talcum powder, occasionally human hair and  small (but significant) proportion of cat urine!

I think that there are a number of significant reasons why the HI-Fi separates last longer.  First, generally, they are better designed and built.  Then there are no high power components and little heat is generated, therefore no, or little ventilation is required and, unless you leave the tray open, little in the way of contamination can get in.

A word about CD lens cleaners...
If you want a definitive answer, I'm not really sure if they do any good or not!  If the type of contamination we're talking about is light dust then they can't do any harm and may even extend the life of your player.  But you must use one frequently.  Anything heavier and the best they are going to do is move it around.  Chances are you'll buy one and forget about it until you have a problem.  No good reaching for it at this stage, it's already too late - if your player won't read a CD it's not going to play the cleaner either.  Time for a new laser!

If you want to know more about how CD players work look here.

I hope that this has been useful, informative or just plain interesting.  As always your comments are invited, as are your faulty CD players!